well, RAID0 on my rig more than doubled my HDD performance according to HDTune, but it is true, raiding SSDs is a bit different from raiding HDDs.
The main issue is that SSDs are very parallel in nature, so larger drives are naturally faster than smaller ones to begin with, and typically moving form a 120GB drive to a 240GB drive provides more performance than RAIDing 2 separate 120GB drives. After 240GB drives tend to start hitting throughput limits, and manufacturers start using higher density memory rather than more memory modules, so at that point RAID begins to make sense.
The loss of TRIM is not a huge issue for modern drives so long as you are not hammering the drives. The drives will do some GC without TRIM, it is just slower and less efficient. But if the drive has some down time, and is not being run full all the time, then it should not be an issue.
Also, RAID initialization time is typically longer than any boot performance you will get to begin with, in my case it adds a net 3 secconds to the boot time compared to not running RAID. However, I am running some older HDDs that are in RAID1 as a temporary fail-safe until I can afford my big RAID5 storage array, so I guess I was going to have that extra load time to begin with. Not a huge noticeable load time difference for most programs, but it deffinately made Premere Pro load a bit faster, and Skyrim transitions were easily cut in half (2-3 sec instead of ~5sec on a single drive) by adding the RAID0. At any rate, my point to adding the 2nd SSD was more a space issue so that I could edit footage from the SSD rather than my aging HDDs, and it was cheaper to add a 2nd 240GB than to get a 480GB and not know what to do with the 240GB I already had, so that worked well.
@stark
your drives cannot be in both RAID0 and AHCI as they are two different settings, so you many want to check your settings to ensure that you are in fact running RAID at all.
If you are in the windows installer and get beyond the point of drive selection then the RAID is not at fault and it is more likely a hardware issue. As the system seems to be stable I would guess that it is either a bad install disc, a bad stick of ram, or a bad SSD in the mix (and possibly more than one of those issues, though that would be unlikely).
Check disc for scratches
Check ram with memtestx86+ for ~2-4 hours per module, and only have 1 module installed at a time
Check HDDs by plugging them into another computer, formatting them, copy files to them, and then run check disc